Electronic devices with displays are used to present various information, such as text, diagrams, pictures, maps, and the like in graphical form as images. Touch-screen displays allow for manipulating images by touching the display at one or more locations and then moving the one or more points of contact in a certain mode. The certain mode of touching of a touchscreen and moving the points are referred to as a gesture.
There are many gestures currently in use. Some of them are simple. For example, to move an image, it is common to touch a point on the screen and then drag it.
A popular method for zooming an image using a gesture is to touch the display simultaneously at two different points with two fingers and then move these points in a pinching or “de-pinching” fashion to zoom in or out. In another example, a Television (TV) meteorologist may manipulate a big map with both of his or her hands; in this case, the “two points” are defined by hands, rather than fingers.
This “pinch” is a popular and intuitive gesture. However, its main drawback is that it requires at least two points of interaction. This method is not applicable in situations when a person holds a smart phone in one hand and cannot use the hand for the manipulations (for example, when someone riding in public transportation is holding a railing, or someone is driving and using a mapping application). In this case it is still possible to perform the touching and dragging comfortably, but not the pinching.
There are other gestures—although not in such common use as pinching—that offer a single-point control for these operations. For example, in some programs, one has to tap the display twice at the location of interest in order to zoom in. In other programs, one has to touch the display and wait a certain time until specific icons appear on the screen and then touch one of the icons in order to zoom in or out. It is also possible to add additional static icons/buttons on the screen to provide this flexibility.
The methods mentioned above have some downsides:
1) Double-tap to zoom in:                a) Performing a double-tap may conflict with other double-tap functionalities; for example, you cannot use double-tap for any other functionality like putting down a pin or launching a website.        b) Double-tap provides only the “zoom-in” functionality, but not the “zoom-out.”        
2) Additional buttons or static icons:                a) The icons take up valuable screen “real-estate.”        b) To touch a button or an icon, one has to release the point being dragged (a point of interest).        c) The location of the buttons may require a significant “travel distance” and may cause one to frequently “re-grip” the device (phone).        d) The buttons do not define a center point for the operation (it is usually hard-coded to be the center point of the screen). So, if a person did not align a point of interest with the center point of the screen prior to the operation, he or she can easily lose that point while, for example, zooming or rotating an image.        
3) Holding down for a period of time:                a) This gesture is slow.        b) It may conflict with simply putting down your finger and lingering a bit too long before starting a dragging operation.        c) Again, it requires the user to “let go” of the point of interest.        
None of the above variants of gestures have been intuitive/simple/useful enough to become widely accepted, therefore there is no unifying standard for a single-point zoom operation.
The technique disclosed herein proposes a new type of gesture, which requires only one point of contact, feels natural, and allows controlling multiple parameters (for example, panning the image, zooming in and out around specific points and, in some embodiments, rotating around the same point); all operations can be done in one smooth motion. In addition, the gesture can be used to control even more parameters; for example, a single motion can be used to control two-dimensional position, scale, rotation, brightness, contrast and saturation of the image.